Greases



Patented Mar. 8, 1949 GREASES John C. Stamm, Chicago, Ill., assignor to Standard Oil Company, Chicago, 111., a corporation of Indiana No Drawing. Application November 20, 1946, Serial No. 711,215

9 Claims.

This invention relates to improvements in the manufacture of rosin oil, and more particularly to an improved method of preparing rosin oil suitable for use in the manufacture of greases.

The destructive distillation of rosin yields distillates of viscous oils known in the trade as rosin oils. The distillation may be carried out @by fire in the usual type rosin still or by fire in the presence of superheated steam. The fractions usually recovered are rosin spirits, distilling at about 160 0., light oil distillates at about 200 C., kidney oil distilling at about 250 C. and bloom oil distilling at about 270 C. Heretofore, it has been the practice in the manufacture of greases, particularly the so-called sett greases, to saponify a mixture of rosin oil and petroleum oil, of suitable viscosity, with calcium oxide or slacked lime under such conditions to produce a grease having the desired setting characteristics. The rosin oil used is the so-called kidney oil; sometimes the so-called bloom oil is used. Rosin-oil usually employed for this purpose contains about 40-50% abietic acid. Although rosin, from which the rosin oil is produced, contains more than 90% abietic acid, rosin per se cannot be employed in the manufacture of cold sett grease since it will not set properly; therefore, since the value of rosin oil as a grease component is in its acid content of about 40-50%, the remaining 50-60% of the neutral oil in the rosin oil is not utilized in the preparation of the soap. Furthermore, the residuum remaining after distilling the rosin oil is not used in the grease making process, and therefore may be considered wasted.

In order to fully utilize the rosin, it has been the practice heretofore to form the rosin oil in situ by heating a mixture of petroleum oil and rosin at a temperature of about 500 F. to about 550 for such a period that the rosin oil produced gives to the grease, upon saponification with lime, the proper setting and consistency characteristics. In order to obtain a rosin oil having the desired characteristics, it is usually necessary to heat the mixture of rosin and oil for a period of about 24 to 44 hours or longer. The duration of heating is determined by sampling the rosin oil periodically, preparing small mixes of grease therefrom and determining the setting time and penetration thereof. The reaction is considered complete when a se'tt grease prepared from lime, mineral oil and the sample of rosin oil sets to a solid gel in 20 to 40 seconds and has an unworked penetration of 150 to 170 by the A. S. T. M. cone penetrometer test at a soap content of 8-10%. Close control of the heating conditions is necessary since if the temperature is too low the reaction time becomes excessive, and if the temperature is 'too high, the rosin acids are rapidly .decarboxylated. This prior method of preparing rosin oil results in a diminution of the rosin acid content from 2 an initial value of about to a final value of 50%, representing a loss of about 23% of rosin acids.

A .copending application, Serial No. 711,193 filed by .Alfred W. 'Weitkamp, November '20, 1946, describes an improved method of preparing rosin oil from rosin in which a mixture of hydrocarbon oil and rosin is heated to about 450 F. in the presence of small amounts of sulfur for hour to 9 hours. While the process is very effective, it presents certain disadvantages in that it requires carefully controlled conditions to obtain the desired degree of conversion. Also the products prepared from the conversion of rosin in the presence of sulfur often have an undesirable sulfur-odor.

It is an object of the present invention to provide a method of treating rosin to make it (suitable for use in the manufacture of cold sett grease. Another object of the invention is to provide an improved method of preparing sett greases. Another object of the invention is to provide a method of treating rosin to produce rosin oils having the property of imparting to greases desirable setting characteristics. Another object of the invention is to provide a method of preparing rosin oils without substantial decarboxylation. Still another object is to provide a more flexible catalytic rosin-conversion process. A further object is to provide a method of catalytically converting rosin to rosin oil free of objectionable odors. Another object of the present invention is to provide a method of rapidly forming rosin oils from rosin in .situ in the preparation of sett greases. Other objects and advantages of the invention will become apparent from the following description thereof.

I have discovered that the foregoing objects can be attained by heating a mixture of from about 10% to about 90%, and preferably from about 20% to about 50% of an active organic sulfur compound or a mixture of organic sulfur compounds, preferably a sulfur-containing hydrocarbon oil such as a sulfurized hydrocarbon oil, or a natural high sulfur mineral oil, for example a suitable fraction from Winkler crude or West Texas crude oil, with from about 10% to about 90%, and preferably from about 50% to about of rosin at a temperature of from about 450 F. to about 525 F., and preferably from about 480 F. to about 510 F. The mixture is heated for a period of time within the range of from about 1 hour to about 12 hours and preferably from about 3 .hours to about 8 hours, the optimum time being dependent upon the temperature and amount and kind of sulfur-bearing oil used. A substantially sulfur-free hydrocarbon oil can, if desired, be used in combination with the organic sulfur compound or sulfur-containing oil.

The present invention is particularly well adapted to the preparation of sett greases which are mixtures of calcium soaps of rosin acids and various grades of mineral lubricating oils. Sett greases which usually contain from about 5% to about 25% calcium rosin soap are usually employed for the lubrication of rough, heavy bearings operating at low speeds, and are used extensively in the logging industry where a relatively cheap grease is required for the lubrication of skidways. They are also used in the lubrication of gears. The following procedure illustrates one method of applying the present invention to the preparation of so-called sett greases. A mixture of 65% K rosin and 35% of a sulfur-bearing distillate mineral oil, such as 300 F. flash Winkler distillate having a Saybolt Universal viscosity at 100 F. of about 80 to 85 seconds and containing about 1.59% total combined sulfur is heated to a' temperature of about 490-500 F. Periodically a sample is withdrawn from the heated mixture, a grease sample prepared containing about 75% mineral oil, 7% water, 3% calcium hydrate and 15% rosin oil, and the time for the grease to set or gel noted. If the grease sets or gels in 20 to 40 seconds and has an unworked penetration of 150-170, the heating is stopped and the finished rosin oil is either pumped to storage or used at once in the preparation of lubricating greases. Depending upon the amount of sulfur-bearing oil used, it will be found sufiicient usually to heat the rosin oil mixture at 500 F- for about 4.5 to 10 hours. By methods heretofore used, about 44 hours would be required for heating the rosin oil mixture to obtain a rosin oil which would produce a calcium rosin soap having the desired setting characteristics. Thus a saving of about 75% of time necessary for the processing of the rosin oil is accomplished,

The advantage of the present invention is clearly demonstrated by the data in Table I in which the 77 F. A. S. T. M. penetration values and setting times for sett greases prepared from mixtures of 65% rosin and 35% sulfur-bearing 300 flash Winkler distillate oil heated at 500 F. for'short periods of time are compared with sett greases from rosin oils prepared by simply heating at a like temperature non-sulfur bearing mineral oil and rosin over long periods of time.

Table A. S. T. M. Penetration at 77F. and Sett Time i in Seconds Catalyst I Heating 357 35% 3 7 $5 3? 802 Pal Dist. 300 Flash 300 Fl ash Winkler Dist. VVinkler Oil 3 Sett Sett Sett Penetra- Penetra- Penetra- Time Tune Time tion see tion .tion Sec 1 802 P. Dist. percent Sulfur .05.O6 percent. 2 Contained 2.02.3% Sulfur 3 Contained 1.60% Sulfur.

The sett greases used in obtaining the above data were prepared to give an A. S.'T..M. penetration at 77 F. of to with a gel or setting time of 20 to 40 seconds. As shown by the above data using 35% Winkler distillate in the production of the rosin oil, a sett grease meeting these specifications can be prepared by heating a mixture for 4 to 8 hours, and with Winkler oil, a lower sulfur-bearing oil, a heating period of about 6 to 10 hours is required. When a non-sulfur bearing oil was used in the preparation of the resin oil, sett greases having the penetration within the specified range were obtained after heating for 7 to 12 hours, but the greases had a setting'or gelling period outside of the specified range of 20 to 40 seconds. Such greases usually required about 50-60 seconds to gel or set. Such rosin oil prepared on a commercial scale does not form a 40 second sett grease until heated 44 hours.

While I have described the invention in connection with the preparation of sett greases, the invention is not limited thereto, but is applicable to the preparation of rosin oils for use in the preparation of greases in general, particularly those prepared by saponifying rosin oils with an alkali metal base, or an alkaline earth base or mixtures thereof, such as oxides or hydroxides, i. e. NaO I-I, CaO, Ca(OI-I)2, Ba(O'I-I)2, LiOH, etc.

It will be understood that any sulfur-bearing lubricating hydrocarbon oil may be employed in producing these greases, i. e. one having a Saybolt Universal viscosity at 100 F. of at least 70 seconds. Additional lubricating assistants suchas graphite, mica, etc. may be employed in such greases.

The present invention herein described provides a process for the production of rosin oil in which the optimum rosin conversion is obtained in a much shorter heating period, resulting in a saving in time, labor and heat. The process also provides a minimum loss in rosin acid through decarboxylation and as a result thereof less rosin oil is required to prepare soaps to give a specified grease consistency. Furthermore, the products have improved color and are substantially free of objectionable sulfur odor.

When used herein and in the appended claims, the percentages given are on a weight basis.

While I have described the preferred embodiments of my invention and the preferred mode of carrying out the same, it Will be readily apparent to those skilled in the art that many variations and modifications may be made therein without departing from the spirit of the invention, the scope of which is limited only by the appended claims. I L

I claim: I Y I r I i 1. The method of preparing a rosinsoap grease comprising heating a mixture of a hydrocarbon oil and rosin at a temperature of from about 450? F. to about 525 F. in the presence of from about 20 weight percent to about 50 weight percent of a sulfur-bearing hydrocarbon oil for a period of time within the range of from about one hour to about 12 hours to produce a rosin oil and subsequently saponifying said mixture of oil and rosin oil. I

2. The method of preparing a rosin soap grease comprising heating a mixture of from about 10 weight percent to about 90 weight percent of a sulfur-bearing hydrocarbon oil and from: about 10 weight percent to about 90 weight percent rosin at a. temperature of from about 450 F. to. about 525 F. for a period of. time within'the'range, of;

from about one hour to about 12 hours and then saponifying the heated mixture with a base.

3. The method of preparing an alkaline earth rosin soap grease comprising heating a mixture of from about weight percent to about 90 weight percent of a sulfur-bearing hydrocarbon oil and from about 10 weight percent to about 90 weight percent rosin at a temperature of from about 450 F. to about 525 F. for a period of time within the range of from about one hour to about 12 hours, then saponifying the heated mixture with an alkaline earth base.

4. The method of claim 3 in which the alkaline earth is calcium.

5. This method of preparing an alkali metal rosin soap grease comprising heating a mixture of from about 10 Weight percent to about 90 weight percent of a sulfur-bearing hydrocarbon oil and from about 10 weight percent to about 90 weight percent rosin at a temperature of from about 450 F. to about 525 F. for a time within the range of from about one hour to about 12 hours, and then saponifying the heated mixture with an alkali metal base.

6. The method of claim 5 in which the alkali metal is sodium.

7. In the preparation of an alkaline earth rosin soap grease, wherein the rosin soap is prepared by reacting rosin oil with an alkaline earth saponifying agent, the improvement comprising heating a mixture of from about 10 weight percent to about 90 weight percent of a sulfur-bearing hydrocarbon oil and from about 10 weight percent to about 90 weight percent rosin at a temperature of from about 450 F. to about for a time sufiicient to produce a product which upon saponification will form a grease having a setting time of from about seconds to about 40 seconds and an A. S. T. M. penetration at 77 F. of from about 150 to about 170.

8. In the preparation of calcium rosin soap grease, wherein the rosin soap is prepared by saponifying rosin oil with a calcium base the improvement comprising heating a mixture of from about 10 weight percent to about 90 weight percent of a sulfur-bearing hydrocarbon oil and from about 10 weight percent to about 90 weight percent rosin at a temperature of from about 480 F. to about 510 F. for about from 4 hours to 12 hours and saponifying the resultant mixture with a calcium base.

9. In the preparation of a sett grease containing from about 1.0% to about 50.0% calcium rosin soap, wherein the rosin soap is prepared by reacting rosin oil with calcium hydrate, the improvement comprising heating the mixture of about 20% to about of a sulfur-bearing hydrocarhon oil and about 50% to about rosin at a temperature from about 490 F. to about 500 F. for about 4 to 9 hours, and subsequently saponifying the mixture of hydrocarbon oil and rosin oil formed with from about 0.1% to about 7.0% calcium hydrate.

JOHN C. STAMP/I.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,109,298 Mariner Sept. 1, 1914 1,243,312 Low Oct, 16, 1917 2,114,843 Kaufman et al Apr. 19, 1938 2,222,591 Clarke et al Nov. 26, 1940 2,359,404 Colgate et al. Oct. 3, 1944 2,431,052 Kalman Dec. 24, 1946 

